The present invention relates generally to electrical power connectors. More particularly, the invention concerns an electrical power connector used with rack-mounted electrical equipment, the connector being attached to the rack and having multiple degrees-of-freedom in movement for receiving a mating connector.
In conventional rack-mounted electrical equipment, a cabinet has vertically spaced rack mountings and a back. Modular components are supported by corresponding rack mountings so that the components can slide into and out of the cabinet. To provide electrical power to the modular components, the cabinet back typically includes one or more continuously powered bus bars and/or back planes. Each modular component normally includes one part of an electrical connector assembly to effect electrical energization when the component slides into the cabinet; the cabinet itself carries the corresponding part of the electrical connector assembly.
Normally the connector assemblies are positioned such that they cannot be visually observed when the mating pieces engage one another. Accordingly, when sliding an equipment module into a rack, alignment between the mating pieces becomes very critical. If the two mating connectors are misaligned then damage may occur to projecting pin connectors or blades mounted on the rack or the equipment module. In the past a commonly used connector has been a clip-type female electrical power connector. Typically, a female power connector is attached to the surface or an edge of a back plane of a piece of electrical equipment, the back plane thus functions as a power supply. The equipment module is slid into a rack usually adjacent to several other pieces of equipment. A complementary male power connector attached to the back of the rack is inserted into a female connector on the back of the equipment module as the module is pushed into the rack. In some configurations, the female connector is attached to the back of the rack while the male connector is carried by the equipment module. In either configuration, the connecting procedure is the same. With these type of connectors, "blind mating" occurs because the mating connectors can not be seen as the male connector is inserted in the female connector.
Some existing female power connectors are simply rigid U-shaped clips bolted to the back plane of the equipment while the male connector element is a simple blade received by the U-shaped clip. One disadvantage to these type of clips is that blind mating is very difficult because the rigid nature of this type of clip does not permit compensation for preexisting misalignment between the male connector and the clip (i.e., female connector). In practice, the equipment tediously has to be moved about and adjusted until the male connector aligns with the opening in the female connector. An additional problem for connectors of this type is that the longitudinal axis of the male and the female elements have to be accurately coaxially aligned. If the male connector is not coaxial with the female connector, then the male connector cannot be fully engaged in the female connector and a poor electrical connection may result.
To address the pre-insertion misalignment problem, the prior art has added a guide 15 (FIG. 1) along side of the U-shaped female connector 3. The guide 15 had an elongated opening 2 laterally aligned with the opening between fingers 4. Moreover, the opening 2 included convergently inclined sides 5, 6. With that arrangement, if there was misalignment between the male and female connector elements, the male connector element will contact one of the slanted sides 5, 6 and cammed into opening 2 so that the male connector can be guided to the location between the fingers 4.
However, a problem still exists with regard to the misalignment during insertion. Occasionally, the axis of the male connector is not be perpendicular to its mounting surface or is not coaxial with the axis of the female connector. Such misalignment impedes the mating connection. For example, if the axis 7 (FIG. 2) of the male connector 11 is not coaxial with the axis 8 of the female connector 3 such that there is a difference .alpha. in the angular alignment, then the male connector 11 will encounter resistance and bind as it is inserted into the opening 2. As a result, a bending stress will be applied to the male connector 11 at the point 10 which may cause damage to the male connector 11. Another disadvantage of this configuration is the small area of surface contact between the male and female connectors--such small areas give rise to power loss, heat concentrations, and other undesirable operating characteristics.
It is, therefore, desirable to have an electrical power connector that compensates for misalignment, both before insertion and during insertion, between the mating elements of the electrical power connector while also providing enhanced electrical contact between the two mating elements.